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(No Model.)

J. E. Mo-KENNA.

CHIMNEY GAP.

Patented Feb. 1, 1887.

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UNITED STATES PATENT OFFICE.

JOHN,E. MOKENNA, OF ST. LOUIS, MISSOURI.

CHIMNEY-CAP.

SPECIFICATION forming part of Letters Patent No. 357,017, dated February 1, 1887.

Application filed June 28, 1886. Serial No. 206,533. (No model.)

To all whom it may concern.-

Be it known that I, JOHN E. MOKENNA, of the city and county of St. Louis, State of Missouri, have invented a new and useful Improvement in Chimney-Gaps, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming part of this specification, in which Figure 1 represents a side elevation ofa chimney-cap embodying my improvements. Fig. 2 is a sectional view of the same on the line :0 w of Fig. 1. Fig. 3 is a cross-sectional view on the line y y of Fig. 1. Fig. 4. is a detail representing a cross-sectional view on line w w of Fig. 2, and showing the flues 6.

My invention relates to chimney-caps, and has for its object to provide a cap for a chimney which will prevent overhead currents of air from entering the chimney by blowing down the same, but which operates to cause currents of air to mingle with the smoke and facilitate the escape of the same.

My invention consists in the peculiar con struction and combination of elements adapted to promote the draft in the chimney and the escape of smoke therefrom, as I shall hereinafter fully describe and specifically claim.

To enable others skilled in the art to make and use my invention, I will now describe its construction and indicate the manner in which I have carried it out.

In the said drawings, A represents a chimney with my improved cap and ventilator applied thereto.

The cap B is divided horizontally at or about its center, to form an upper and a lower section, at, the two sections being secured together by any suitable means. The lower section, b, is designed to rest upon the top of the chimney, and it is provided with upwardly-extending sides 0, having a series ofopenings, d, through which the currents of cold air pass to the interior of the cap. In addition to these side portions, the lower section of the cap has projecting from its center a tube 0, whose cross-sectional configuration is square or rectangular, and is preferably of a diameter approximating the interior diameter of the chimney. The upper section, a, is of conical form, closed at the top and side, whereby it forms an air-chamber, into which the air passing through the openings 0 in the lower section enters. This upper section is provided with a cylindrical or oval tube, D, which is of sufficient length to project slightly above the top of the upper section and extend downward a considerable distance (two feet, more or less) into the flue of the chimney. This tube being cylindrical or oval, and the tube 0 inthe lower section, through which it passes, being square or rectangular, it is manifest a flue, 6, will thus be formed in each of the four corners of the tube 0, and it is through these flues e that the air which enters through the side openings, d, into the upper section, a, passes.

The chimney-flue being about the same'di' ameter and configuration as the tube 0, and the tube D extending into the flue in the manner described, it is evident there will be formed between the inner walls of the chimney and the exterior of the tube D fines d, which correspond and are in alignment with the fiues e, formed between the said tubes 0 and D, as shown in Fig. 2.

From this description it is manifest the outside air passes through the openings d, from whence it descends through the flues e d to the bottom of the tube D, where it meets the ascending heated air and smoke and pro- -motes the draft and escape of smoke from the chimney.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. The lower section, I), having openings (1 in its sides and a square or rectangular tube projecting from its center, in combination with anuppersection having a depending tube which forms between itself and the tube 0 a series of fines, substantially as described.

2. An improved chimney-cap dividcdhorizontally into an upper closed section having a depending cylindrical oroval tube and a lower section having a square or rectangular tube,

0, forming between itself and the tube D a se ries of dues, substantially as herein described.

JOHN E. MOKENNA. Witnesses:

THOMAS KENNY, L. F. BORNTRAEGEB. 

